The Storm Prediction Center has placed large stretches of the northern Plains under back-to-back Severe Thunderstorm Watches on Tuesday, as supercells already raking the Dakotas hurled hail up to ping pong ball and golf ball size and packed 60 mph wind gusts.
Forecasters warn the dangerous afternoon-to-evening window has hours left to run.
Two Watches, Four States
The broader of the two alerts, Severe Thunderstorm Watch 270, covers a vast 34-county block of central and northern North Dakota — including Burleigh, Ward, Morton and Stutsman counties — and runs until 10 p.m. CDT. Just to the south, Watch 269 stretches across western South Dakota, the Nebraska Panhandle and southeastern Wyoming, in effect until 9 p.m. MDT.
Together the watches blanket the Rapid City, Bismarck and Scottsbluff areas, with the Storm Prediction Center flagging large hail, damaging gusts and a couple of possible tornadoes as storms fire along a surface low developing near the Wyoming–South Dakota–North Dakota border.
Storms Already Doing Damage
A watch means conditions favor severe storms; warnings mean they have arrived — and several were already flying. In Oglala Lakota County, South Dakota, the NWS Rapid City office warned of ping pong ball size hail near Oglala and Manderson, with an unusually stark impact line: “People and animals outdoors will be injured,” the bulletin cautioned, urging residents to move to an interior room on the lowest floor.
Farther north, a storm over Haakon and Jackson counties carried a considerable damage threat with golf ball size hail confirmed by trained spotters at Cactus Flat. That cell tracked across Interstate 90 between mile markers 127 and 143, near the Minuteman Missile site, threatening torrential rain and flash flooding. In Wyoming, the NWS Cheyenne office warned of quarter-size hail and 60 mph gusts along Interstate 25 near Chugwater.
The Setup
The outbreak is being driven by a slow-moving upper-level disturbance and strengthening mid-level winds across the western Dakotas. As the National Weather Service notes, severe storms remain possible across the northern Plains through Thursday, with large hail, damaging winds and possible tornadoes — and a fresh round of large-to-very-large hail expected Wednesday into the upper Mississippi Valley.
This corner of the country has a history of fast, violent June storms. The same region produced a destructive thunderstorm complex in June 2025 that delivered 90-plus mph wind gusts and giant hail, underscoring how quickly Plains supercells can turn dangerous.
Staying Safe
Officials stress the basics: get inside a sturdy building, move to the lowest floor, and stay away from windows. Drivers should be especially cautious of hail-covered roads — the Rapid City office likened deep hail to “slushy roads,” advising motorists to slow down and avoid braking suddenly. With torrential rain in some cells, the Turn Around, Don’t Drown rule applies to any flooded roadway. Residents across all four states should keep phone alerts and a weather radio close until the watches expire Tuesday night.
